Data brokers who collect and share vast amounts of information about our lives can make dangerous inferences and create security risks by unnecessarily storing the information, the Federal Trade Commission warned Tuesday in calling for Congress to address the issue.

The FTC said Congress should enact legislation to give consumers more control over the immense amounts of personal information that data brokers collect and share.

“The extent of consumer profiling today means that data brokers often know as much – or even more – about us than our family and friends, including our online and in-store purchases, our political and religious affiliations, our income and socioeconomic status, and more,” FTC Chairwoman Edith Ramirez said in a statement. “It’s time to bring transparency and accountability to bear on this industry on behalf of consumers, many of whom are unaware that data brokers even exist.”

Consumer data often passes through multiple layers of data brokers sharing data with each other. In fact, seven of the nine data brokers in the commission study had shared information with another data broker in the study.

Data brokers combine and analyze data about consumers to make inferences about them, including potentially sensitive inferences such as those related to ethnicity, income, religion, political leanings, age, and health conditions. Potentially sensitive categories from the study are “Urban Scramble” and “Mobile Mixers,” both of which include a high concentration of Latinos and African-Americans with low incomes. The category “Rural Everlasting” includes single men and women over age 66 with “low educational attainment and low net worths.” Other potentially sensitive categories include health-related topics or conditions, such as pregnancy, diabetes, and high cholesterol.

Many of the purposes for which data brokers collect and use data pose risks to consumers, such as unanticipated uses of the data. For example, a category like “Biker Enthusiasts” could be used to offer discounts on motorcycles to a consumer, but could also be used by an insurance provider as a sign of risky behavior.